1. Division of Infertility and Reproductive Endocrinology, Department of Gynecology, Obstetrics and Gynecological Oncology, Poznan University of Medical Sciences, Poznan 60‑535, Poland
2. Department of Anatomy, Poznan University of Medical Sciences, Poznan 60‑781, Poland
3. Department of Histology and Embryology, Poznan University of Medical Sciences, Poznan 60‑781, Poland
4. Department of Obstetrics and Gynecology, University Hospital and Masaryk University, Brno 601‑77, Czech Republic
5. Veterinary Center, Nicolaus Copernicus University in Torun, Torun 87‑100, Poland
6. Division of Histology and Embryology, Department of Human Morphology and Embryology, Wroclaw Medical University, Wroclaw 50‑368, Poland
7. Department of Toxicology, Poznan University of Medical Sciences, Poznan 60‑631, Poland